85z28iroc

iTrader: (1)

I ran a Holley 4777 20 years ago in a 74 Nova SS 375HP 350. I was pleased with its performance and mileage. I have an Edelbrock 1406 in my Camaro and am wondering if this Holley would be a better carb, even though the technology is atleast 20 years old. I realize that one is a little larger, but which is better for both performance and mileage?

Ironmahn

A under fueled engine will run faster than a over fueled one... with in reason. Double Pumper will kill the gas mileage when you stand on it, but what doesn't right!?! The 650 CFM would be better if the engine is built up.

Tobias05

hmm...i like certain things about each one. the edelbrock you can change jets w/o dumping fuel everywhere, and the holley you can adjust the floats externally.

i've messed around w/ an edelbrock a good bit, everything from a stubstack, to accelerator nozzles, springs, rods, and jets. i also netted 24MPG on a slipping 700r4 while cruising at 80. pretty good there.

i'm teaching myself how to tune a holley, and dave emanual has a great book on that same topic. but i see you've been in the business for 20 years, so i'll assume you know what you're doing!

edelbrock seems to be a tune and forget, that also gets pretty good gas milage. having a 3rd transition circuit is nice too.

however i think you'd be able to get more performance from a holley. i have a 4160 1850 right now, but i'm eyeing a 650DP. gotta learn first, then i'll buy the nicer one.

just messing with pump shot, accelerator cams, and shooters i feel the holley has a lot more potential, and i haven't really even gotten into the meat and potatoes of it yet.

in my opinion an edelbrock is gonna edge a holley in gas milage, but a holley is capable of more performance, due to more in depth tuning. MHO, of course.

I'm no expert, by any means, but my vote would go to the 650DP.

Just another student in the art of horsepower.
brandon

five7kid

iTrader: (14)

What exactly does that mean?

Any carb will kill gas mileage when you "stand on it". Under "normal" driving conditions, there isn't any reason a properly tuned 4777 would provide worse fuel economy than any other similarly sized open loop carb. If an Edelbrock gives you better mileage than a 650 DP, you don't have the DP tuned correctly.

A 650 DP is on the slightly large size on a 305 for going WOT off-idle with stock stall. Otherwise, say 350 or higher stall, it will be just fine and with basic tuning out-run the most tweaked-out Edelbrock (or vacuum secondary, or any demand-based secondary carb, for that matter).

Air_Adam

I'm with Five7... theres no reason a properly tuned Holley can't get the same gas mileage and have the same driveability as any other carb of a similar size. Its all just a matter of tuning. The 650 is a bit on the big side for a stock-stall 305, but it should still work just fine if you drive it with a little more finesse. As far as technology goes, I'd bet the Holley is about on par with the Edelbrock... the Edelbrock carbs aren't a new design, they just basically copied the Carter AFB, which is just as old as a 4150 Holley.

Just for the record - I've used a CC Qjet, Holley 750 VS (3310), and 650 DP (4777) on my 350, and the 650 was by far the best performing carb, and all 3 carbs got about the same gas mileage under normal driving conditions.

zz4monte

I agree I have a 650DP and I can tell you gears or stall speed will have a greater effect of gas mileage or your driving habits in general.My zz4 gets 13 mpg when I drive nice.I can easily get 7mpg if I floor it everywhere.Generally speaking the DP is a little better on performance too. I went from a 750rework q-jet to a 650DP and power difference was for sure.Even though the 750 was bigger you could feel the throttle response and low end torque difference from the 650DP.Plus I think the DP is a hell of alot easier to tune.

85z28iroc

iTrader: (1)

When I first purchased that 4777 a long time ago, it was listed as a Competition/Off Road Carb. I had it on a 350 with an old Torker intake, a lopy cam, headers and a Muncie21. I was lucky to get 7mpg, but it sure was fun. I replaced it with a Holley 6619 and really increased my gas mileage, but lost alot in performance. I kept it, all these years, and now was thinking about putting it on my 350 in my Camaro, along with an EPS Performer intake, ported and polished 416's, Comp 268 cam, 1 5/8" shorty headers, but still stock stall and 3.42's. Will that be a good fit?

Air_Adam

The 4777 is listed as a "competition/off road" carb because its not emitions legal. It has nothing to do with how driveable it is, or anything like that. If it was truly only a "competition carb" then it wouldn't have a choke, now would it? Its perfectly fine for street duty. I have one, and I liked it. I've got mine off for cleaning and rebuilding right now, but I do plan to use it again once thats done.

What are the specs of the 6619? I couldn't find any carbs with that PN. If you want something a little more street-oriented though, something like the 1850 Holley might be a good choice for your 305. Its a 600cfm, square bore vacuum secondary carb. That one would be about the same as the Edelbrock 600cfm, performance-wise.

My vote is still for the 4776 or 4777 though. The 4776 is the same as the 4777, but with a 600cfm rating, instead of 650. Either would be great on a 305 though.

85z28iroc

iTrader: (1)

The 6619 was a Model 4160 600 cfm 4 barrel with vacuum secondary and electic choke, very similar to the 1406 Edelbrock. Thanks for sharing your opinion, I guess I will dust off the 4777 and put to use. What intake, cam and heads are you running with yours?

Air_Adam

I'm using an RPM air gap intake, XE274 cam, and a set of lightly modified 601 castings on my 350. Those heads give it a CR right around 11:1... I hadn't planned on it being that high, but thats just how it worked out for me lol. Its a really nice combo, especially with the 4-spd manual I have behind it. Its got MONSTEROUS mid range torque.. Even with 3.23 gears, I can stomp the throttle from a 2700rpm cruise in 4th gear and get the back end to kick out sideways! It feels like the torque builds up (when you hit the throttle) so much faster with the double pumper.. it couldn't do that before with the vacuum secondary carb, even with everything else exactly the same.

Ironmahn

That means that a leaner fuel mixture will have better throttle then a over fueled setup drowning out the engine. Hence my statement...

And to the "stand on it" maybe you missed the ", but what doesn't right!?!" after the stand on it. Dump Pumpers are know for bad fuel economy, I know I have run them. I hope that clarifies everything up. Cheers...

five7kid

iTrader: (14)

Lean vs. rich has nothing to do with Edelbrock vs. Holley. But, lean certainly has more potential for doing damage.

I did see your "what doesn't" comment. Your follow-up comment about DP's doesn't follow, either. A double pumper might use slightly more fuel at WOT than a demand-based secondary design carb (because it's making more power under the curve), but that has nothing to do with economy in normal driving. Poor tuning and driving habits have a lot more to do with poor DP economy. I know, I've run them.

zz4monte

I am with five7kid on this.You might lose 1mpg with the DP but it is nothing really measurable.Let's put it this way if you have two exactly the same cars and everything is the same expect one is a DP and one is a edelbrock,carter,q-jet........whatever. Drive all of this cars around and the person who has better driving habits will have better fuel economy. Like I said I went from a 750 Q-jet to a 650DP and my fuel economy was no different.Now when I put the GN 8.5 in with 3.42's instead of the old 3.73's in the 7.5 I noticed about a rough gain of 1.5 miles per gallon.Your foot and crusing rpms has more to do with it the mech.or vacuum secondarys.

Ironmahn

I see this going nowhere, you all have fun! Later!!!!

five7kid

iTrader: (14)

Trust me, I don't like getting into these playground "my dad's carb is bigger than yours" arguments. However, on the outside chance that 3 years from now someone actually uses the search function and comes across this thread, I can't let inaccurate information go unanswered.

85z28iroc

iTrader: (1)

I think the discussion and different points of view were good. I get from it that the DP is a better performance carb, and still can be just fine for gas mileage. I think some people shy away from DP because they are scared of what might happen to their gas mileage. This tells me that that is not necessarily the case.

Air_Adam

That does about sum it up, I think

Huron

Noticed the posts about carbs and fuel economy. Actually, there can be a large difference. Here, I documented a 14% difference between running the very quick and clean Holley 6619 and a 7029207 Quadrajet. It was a Qj -vs- Holley test that I ran some years back, where I compared a Holley with 3 Quadrajets.

Link:

http://www.chevelles.com/forums/showthread.php?p=477716

Best Regards,

Mike

Air_Adam

The quadrajet is quite a different from the Edelbrock (carter) carb that the Holley was being compared to. I'd take a Qjet over an Edelbrock (carter) anyday - better performance, better gas mileage, and better driveability.